I got WA. tested all the inputs in udebug..
I've searched for AC codes in google and there are so many ac codes with double type and ceil function like my code. Then what's wrong with my code..?
Here's 2 links of AC code's:
(Links are deleted after getting ac)
Here's my code... plz help...

To brainfry,
can't understand, what should i use instead of floating point ?? how can obey this condition "If the calculated tax is a floating point then it must be replaced by the smallest integer greater than the payable tax." without using floating point

Actually Brainfry is right. It is always better to avoit floating point calculation because it is very easy to get precision error or other mistakes.
For this problem to avoid floating point you could multiple by some constant number to work only with integers. You could use long long for tax and all values of tax keep multiplied by 100.

However I solved this problem with floating point. You must be very very careful in this case. In your code you have integer division mistake. You must convert to double to avoid integer divison. It can be done in different ways.
Change your code to

Hi guys,
I am getting WA consistently. I have checked Inputs frm uDebug. I found that my code doesn't allow me to work with the numbers like 10000000000 and few more like this.
How can I deal with such long floats...? Is there any way ?